1. Field of the Invention
This invention relates to communication systems. In particular, this invention relates to providing secure communication for wireless devices.
2. Description of Related Art
At least hundreds of millions of dollars are lost annually to unauthorized calls made from communication devices. In particular, unauthorized callers are able to clone wireless phone systems by intercepting the control signals passed between the wireless unit, such as a mobile phone unit, and a local base station. This interception usually occurs during a call set-up. It is relatively straight forward to clone wireless phone systems since most wireless unit identification numbers and phone numbers are static or are changed only with the movement of the mobile phone unit from one cell to another. In order to help alleviate the lost revenue attributable to unauthorized calls, some phone companies have initiated a pin number requirement which must also be dialed in addition to the called party's phone number, and other companies are using types of encrypted authentication.